.container { 
  width: 400px;
  height: 600px;
  border: 2px solid gray;
  background-color: #f4f2f4;
  border-radius: 8px;
  padding: 16px;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
}

.header {
  margin: 0;
  margin-bottom: 16px;
}

.screen {
  height: 20%;
  border: 2px solid '#DDD';
  border-radius: 12px;
  display: flex;
  justify-content: flex-end;
  font-size: 24px;
  font-weight: bold;
}

.btnWrap {
  flex: 1;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}

.btn {
  user-select: none;
  cursor: pointer;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 86px;
  height: 19%;
  background-color: #fff;
  font-size: 22px;
  /* font-weight: bold; */
  border-radius: 6px;
  box-shadow: 2px 2px 4px 0 rgba(0, 0, 0, .1);
}

.equalBtn {
  user-select: none;
  cursor: pointer;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 178px;
  height: 19%;
  color: white;
  background-color: #1158bd;
  font-size: 22px;
  /* font-weight: bold; */
  border-radius: 6px;
  box-shadow: 2px 2px 4px 0 rgba(0, 0, 0, .1);
}